Abrasives are commonly used in industrial and commercial applications to impart a desired surface finish or treatment to a substrate. The breadth of these applications explains the countless structural and chemical varieties of abrasive solutions presently available on the market.
One type of abrasive composition is based on a compound made from hard particles suspended in a soft medium such as a liquid, paste, or wax. These compositions can be disposed on a suitable backing, such as a cloth or buffing pad, and then rubbed onto the substrate to remove scratches. The rubbing process can be carried out by hand or assisted with a motorized tool. The liquid, paste, or wax acts as a binding agent that retains the particulate abrasives on the backing and enables the particles to move across and act to polish the substrate. In some applications, the binding agent can serve both a protective function that seals the surface against air and moisture and an aesthetic filler that makes scratches left behind less noticeable.
The marine industry is a specialized area that presents unique challenges to abrasive finishers because of the nature of the substrate. Marine vehicles are typically coated with a gelcoat, which is used to provide a high-quality finish on the exposed surfaces of a reinforced composite material. Gelcoats are often based on epoxy or unsaturated polyester resins specially formulated with thixotropic ingredients for increased viscosity and non-sag properties, and can be pigmented for color. These compositions are highly crosslinked and extremely tough. Over time, gelcoats can oxidize from ultraviolet light exposure, resulting in a chalky appearance. While this oxidation is a surface phenomenon, it can nonetheless be difficult to remove because of the intrinsic toughness of the gelcoat.